Railway truck



Nov. 23, 1937. o. BARROWS, 2,100,181

RAILWAY 'raucx Filed Nov. 24, 1954 4 Sheets-Shet 1 Nov. 23, 1937. D. s. aAr'afzaws 2,100,181

7 RAILWAY 'rnucx Filed Nov. 24, 1934 4 Sheets-Sheet 2 Dave/.0 dBPPP ws Patented Nov. 23, 1937 PATENT OFFICE RAILWAY TRUCK l Donald S. Barrows, Rochester, N. Y., assignor to The Symington-Gould Corporation, Rochester, N. Y., a corporation of Maryland Application November 24, 1934, Serial No. 754,659

18 Claims.

, This invention relatesto railway trucks and,

e the springs of the nests in proper relation with respectto one another and the associated frames, said plates being particularly adapted to more positively retain the bands of the elliptic springs in normal position.

Another object of my invention is the provision of a spring plate, for bolster springs involving a banded leaf or, elliptic spring, provided with a relatively thick or'cast portion rigidly connected to or connecting relatively thin pressed plateportlons, said cast portion being alternatively apertured for permitting the passage of the band means ofsaid leaf spring, and said pressed por- ,tions being desirably provided with centering means for helical springs. v

Other objects and advantages of the invention relating to the particular arrangement and construction of the various parts will become apparentas the description proceeds,

. Referring to the drawings illustrating my invention, the scope whereof is defined bythe appended claimsz- I s Figure 1 is a fragmentary side elevational view of a-railway truck embodying my invention.

Figure 2 is an elevational view, with the upper spring plate shown in central vertical section, and the adjacent set of helical springs removed. of the nest of springs shown in Figure 1 detached from the truck and looking in a direction at right angles to thatof Figure 1.

Figure 3 is a plan of the nest of springs shown in Figures 1 and 2, a portion of the upper spring nlate being broken away and the associated helical springs only fragmentarily illustrated.

.Figure 4 is a detail planof one of the interchangeable spring plates shown in Figures 1, 2 and 3. slightly modified. c

Figure 5 is a partial end elevation and partial sectional view on. the line 5-5 of Figure 4, looking in the direction of the arrows.

Figure 6 is a partial side elevation and partial vertical sectional view onthe line 6-6 of Figure 4. lock ng in the direction of the arrows.

Figure'lis a fragmentary sectional view on the linel-I of Figure 4 and on a larger scale.

Figure 8 is a fragmentary sectional view on the line 8-8 of Figure 4 and on a larger scale. 0 Figure 9 is a plan of one of the pressed metal portions of the plate detached from the cast connecting portion.

Figure 10 is a side elevational view of the pressed portion shown in Figure 9.

Figure 11 is a sectional view on the line il--ll of Figure 9, looking in the rows and on a larger scale.

Figure 12 is a blanking diagram indicating a preferred method of cutting the blanks from a strip of sheet metalpreparatory to making the pressed metal portions illustrated inFigures 9, 10 and 11. e l e e Figure 13 is a fragmentary view corresponding to Figure 4, but showing another embodiment of my invention.

' Figure 14isa sectional view onthe line "-14 of Figure 13, looking in the direction of the arrows. y

Figure 15 is a sectional view on the line l5l5 of Figure 13, lacking in the direction of the arrows.

Figures 16, 17 and 18 are views corresponding, respectively, toFigures 13, 14 and 15, but showing a further embodiment of my invention. Figure 19 is a detail sectional view on the line l9--I9 ofFigu re 16.

Figures 20, 21 and 22 are views corresponding, respectively, to Figures 13,14 and 15, but showing a still further embodiment of my invention.

Figure 23 is a fragmentary plan corresponding to Figure 4, but showing another embodiment of my invention.

Figure 24 is a sectional view on the line 24-24 of Figure 23, looking in the direction of the arrows.

Figure 25 is a fragmentary sectional view on the line 25-25 of Figure 23, looking in the direction of the arrows.

Figures 26, 27 and 28 are views corresponding, respectively, to Figures 23, 24 and 25, but showing a further embodiment ofmy invention.

Figures 29 and 30 are views correspondingrespectively, to Figures 13 and 14, but showing an additional embodiment of my invention.

Figure 31 is a fragmentary sectional view on line 3i3l of Figure 29 and'on a largerscale.

Figure 32 is a fragmentary view corresponding to Figure 31, but showing a still further embodiment of my invention.

Referring to the drawings in detail, like parts being designated by like reference characters, and first considering the embodiments of my invention illustrated in Figures 1 to 12, inclusive, there is shown a portion of a railway truck I involving a pair of side frames 2, only one of which is illustrated, receiving the ends of a bolster 3, only one end of which is illustrated. The bolster 3 extends into the window openings 4 of the frames direction oi the ar- 2, each window opening being defined by a compression member 5, a tension member 6, and bolster guide columns 1. Supported at each end on the tension member of a frame beneath the window openings 4, in the present embodiment, is a spring plank 8, between each end of which and the corresponding end of the bolster 3 is a nest of springs 9 disposed in the corresponding window opening 4.

In the present embodiments, each nest of springs 9 comprises four helical or coil springs or spring units I0 and an elliptic or banded leaf spring, or series of leaf springs held together by bands or band means, l3. Each spring ll comprises a stack or series of curved spring leaves l2 held together intermediate their ends by bands l3 and divided into upper and lower groups with their end portions separated by end blocks l4, in accordance with the usual practice for full elliptic springs.

In order to center or hold the elliptic and coil springs in proper position between the bolster and spring plank, or bolster and frame, if the spring plank is omitted, I employ preferably interchangeable upper and lower composite spring caps or plates l5 and I6, said plates being formed to either surround the spring bands, as in Figs. 1, 2 and 3, or provide pockets l5 defined by relatively. thin sprlng-band-engaging webs l6, as in Figs. 4 to 8, inclusive, the upper or inner surfaces of which are desirably partially concave, as illustrated, as well as being provided with collars l1 extending toward the collars on the associated plate and normally surrounded by the associated coil or helicalsprings for centering purposes. The spring plates also directly engage the adjacent ends of the coil springs and, if of the form illustrated in Figs. 1, 2 and 3, provide elevating seats for said springs closer to one another than the seats for the elliptic spring bands which are, respectively, the bolster and spring plank or bolster and frame, thereby avoiding overstressing the leaves of said elliptic spring or allowing for a greater travel of said spring than would otherwise be permissible.

Each plate or cap l5 and I8 comprises pressed or relatively thin portions I8 rigidly secured to and connected by a relatively thick'preferably cast portion IS. The pressed portions i8 are those provided with the collars ll for centering the helical springs and the cast portion i9 is that provided with the aperture 20, (as in Figs. 1, 2 and 3) or the pocket i5, (as in Figs. 4 to 8, incluslve,) to allow for the reception of the spring band, thereby assuring that the portion I! will surround said band and maintain the desired relation between the elliptic spring and the helical or coil springs.

' The pressed portions l8 comprise partially circular, relatively wide, end portions 2| connected by relatively narrow portions 22 embossed or bent out. of the plane of the end portions 2! in the directionin which the collars I! extend and provided with a flange 23 turned down or toward the plane of the end portions 2|. As an additional means for securing a firm interlock between the pressed portions l8 and the cast portion I8, said pressed portions may, in addition, each be provided with a slot 24 and apertures 25, as shown most clearly in Figures 9, 10 and 11. For economy in manufacture, the blanks for the pressed members l8 are desirably cut in accordance with the blanking diagram of Figure 12.

The portion I9 is desirably cast in a mold with the associated pressed portions l8 in position so that the molten metal used in making the cast portion flows around the connected portions of the pressed portions 18 and through the slots 24 and holes 25, thereby insuring a firm connection after cooling, as indicated in Figures 4 to 8, inclusive. The cast portion l9 desirably comprises the relatively thick side portions 26 surrounding the flanges 23 and adjacent portions of the pressed portions I8, as shown most clearly in Figures 4, 5, 7 and 8, and the relatively thin connecting portions 21 desirably provided with channels 28 for maintaining the section as light as possible while seeming the desired strength.

From the foregoing disclosure, it will be seen that I have provided composite plates for nests of springs involving both elliptic and helical or coil springs, said plates comprising relatively thin or pressed metal portions connected together by a central rigidifying portion which is desirably cast in situ, thereby avoiding the necessity for separate securing devices such as rivets, or the like.

The reason for the embossment of the relatively narrow portions 22 of the, pressed portions l8 of the plates is so that they will nest with corrugations 29 in the spring plank 8, which corrugations are formed to provide for clearing and interlocking with the auxiliary reinforcements 30 which are disposed in the lower corners of the window opening 4 of a frame such as illustrated, and in accordance with the Barrows Patent No. 1,652,808 of December 13, 1927, or directly with said reinforcements 30 upon omission of the plank. The bolster, plank, or frame-engaging surface of each plate is desirably generally flat, as illustrated, thereby providing a satisfactory shimming face.

The relatively thick or cast portion 19 of each plate has the relatively thin or low connecting portions 21 which correspond with the thickness of the band and are adapted to lie on either side thereof along the width of the corresponding outer spring leaf. The ends of said relatively shallow portions 21 arejoined by the relatively high portions 26 which are properly higher than the portions 21 because they are beyond the sides of the leaves of the elliptic spring II and, therefore, may extend to heights greater than the mere thickness of the band. Said higher portions 26 comprise not only straight portions extending between the shallow portions 21, but angular extensions aligned with said'portions 27, whereby the corner portions of each band are engaged by relatively tall centering ribs or flanges, the extreme end portions of which are adapted to engage the sides of the associated spring leaf or outer leaves, whereby the elliptic or banded leaf spring is efliciently centered or held in proper position.

As will be seen from Figure 12, the strip 3| of sheet metal, from which the blanks i8 are cut, is desirably of a width corresponding with the width of the partly circular end portions 2|, plus the width of the relatively narrow connecting portions 22, so that the blanks may be cut from said strip, as illustrated, with the avoidance of unnecessary scrap.

Referring now to the embodiment of my invention illustrated inFigures 13, 14 and 15, a form of spring plate i6 is there shown comprising pressed or relatively thin portions l8 rigidly secured to and connected by relatively thick preferably cast portions i9". The pressed portions i8 are provided with collars H"- for centering the helical springs, and the cast portions HI is 65 a transversely of said pressed portion so asto prothat provided with the aperture lflezto allow for the reception of the spring band of the associated elliptic spring, as in the;first embodiment.

, The pressed portions)!!!- comprise elongated strips of sheet metal with their ends curved preferably concentric with the helical spring centering collars i1" and formed with tabs 32 and 33 slit-and bent upfrom' aplane of the plate, as illustrated, so as to provide for the secure interlocking with the cast portion l9. Each plate I8 1 is also desirably provided with a centering nib 34 adapted to fit in a corresponding pocket in the wing the cast portion flows around the tabs and lntothe pocketiormed in, making the embossed nib 34,.resulting' in a firm connection after cooling, as illustrated. Thecast portion '9' desirably comprises the relatively thick side portions 26' desirably bevelled, as indicated at 22, to clear the plank embossments 29 or side frame reinforcements 30 and provided with relatively tall ribbing 35, the ends of .which taper to gradually merge into the end portions of the part IS, angularly disposed portions 36 being provided to frame the corners of the opening thereby providing, as in the previousembodirnent, the relatively low portions 31 corresponding in height with the thickness of the spring band, thereby providing seats for the elliptic spring corresponding with the web I 6' of'Figs. 4, 5, 6 and 8, and

.extending distances corresponding with the width vention illustrated in Figures 16 to 19, inclusive,

a form of spring plate [6 is there shown comprising pressed or relatively thin portions l3 rigidly secured to and connected by relatively thick preferably cast portions I9 The pressed portions l8 are provided with collars 11 for centering the helical springs and the cast portion 19 is provided withan aperture 20 for receiving the spring .band ofthe associated elliptic spring or banded-leaf spring, as in the first embodiment.

The portions l8 comprise elongated strips of sheet metal with their ends desirably curved concentricwith the helical spring centering collars ll and each formed with a lateral extension 33 adapted to underlie thecast portion IS That part of each pressed portion adjacent the extension 38 is desirably slotted,'as indicated at 39, toallow for the embossment of strips 40 and ll, the strip 40 extending in one direction, or longitudinally of the pressed portion 18 and the strip 4! extending at an angle thereto, or

vide for the secure interlocking with the cast portion i9. Each plate H3 is also desirably provided with a, centering nib 34' adapted to fit in a corresponding pocket in the bolster, spring plank or frame with which associated.

The portion Hl is desirably cast in a mold with the associated pressed or plateportions 18 in position so that the molten metal used in making tions II and II through the slots 33 and between said embossed, portions and the body of the pressed portion, resulting in a firm connection after cooling, as illustrated. The cast portion I! desirably comprises the relatively thick side portions 26" desirably bevelled, as indicated at 22', to clear the plank embossments 29 or side .frame reinforcements 30, and provided with ribring 35' the ends of which terminate in angular portions 36'? aligned with the edge portions between said ribbing 35". The ends of said angular portions are desirably Joined to the body of the cast portion by angular gusset portions 42. This constructionof the cast portion of the composite spring plate provides, as in the previous embodiment, the relatively lowportions 31 corresponding in height with the thickness of the spring band, and extending distances corresponding with the width of the spring leaves or ieafsprings encircled by said band, and the portions 35 and 36 considerably higher and disposed beyond the sides of the leaves so as to engage not only the sides of the spring band, but also the edges thereof and the sides of the adjacent spring leaves,

thereby serving to efiiciently hold the leaf spring in proper position. i 1

Referring now to the embodiment of my invention illustrated in Figures 20, 21 and 22, a form of spring plate [8 is there shown comprising pressed or relatively thin portions i8 rigidly secured to and connected by relatively thick preferably cast or drop forged portions |9. The pressed portions l8 are provided with collars I 1, for centering the helical springs, and the cast or drop forged portion |9 is provided with an aperture 20 to receive the spring band of the associated elliptic, semi-elliptic or banded leaf spring, asin the first embodiment. 1

The pressed portions 18 comprise elongated strips of sheet metal with their ends curved preferably concentric with the helical spring centering ribs |1 and each formed with a centeringnib 34 adapted to fit ina corresponding pocket in the bolster, plank or frame with which associated.

The portion l9 is illustrated as connected to the pressed or plate portions I8 by rivets 39, the heads of which are desirably countersunk, as illustrated. The portion i9 desirably comprises the relatively thick side portions 26 comprising webs 22 offset upwardly or in the direction with which the collars ll extend so as to clear the plank embossments 29 or side frame reinforcements 30, and provided with ribbing 35, the ends of which taper and gradually merge into the end portions of the part l9, angularly disposed portions 36 being provided to frame the cornersof the opening 20. This construction provides, as in the first embodiment, relatively low portions 31 corresponding in height with the thickness of. the spring band and extending distances corresponding with the width of the spring leaves or leaf springs of the associated spring and the portions 35 and 36 considerably higher and disposed beyond the sides of the leaves so as to engage .not only the sides of the spring band but also the edges thereof and the sides of the adjacent spring leaves; thereby serving to efiiciently hold the banded leaf spring in propel-position.

Referring now to the embodiment of my invention illustrated in Figures 23, 24 and 25, a form of spring plate I6 is there shown comprising a relatively thin pressed portion I8 rigidly secured to and rigidifled by relatively thick portions IS.

The pressed portion I8. is provided with collars H for centering thehelical springs and formed with an aperture 20 to allow for the reception of the spring band of the associated elliptic spring.

The relatively thin portion comprises elongated side portions 43 joined by end portions 44 for surrounding the band receiving aperture 20. Said portion i8 is also desirably provided with a pair of centering nibs 34 adapted to fit in corresponding pockets in the bolster, plank or frame with which associated.

Each portion 19 comprises a relatively narrow strip of metal thicker than that forming the portion I8 and with its ends bent outwardly or at right angles to the body thereof and normally passing through slits in the portion l8 the juxtaposed part of said relatively thin portion l8 being off-set, as shown most clearly in Figure 25, so as to provide for receiving the portion l9 with its lower surface flush with the lower surface of the plate l8 The plates l8 and I9 may then be secured together by spot welding or riveting, as indicated by the reference character 39 thereby providing seats for the associated elliptic spring corresponding with the portions 31 of Figs. 13, 14 and 15.

The end portions 44 are desirably bevelledi or bent at an angle, as shown most clearly in Figure 24, to clear the plank embossments 29 or side frame reinforcements 30] The outstanding por tions 36 of the relatively thick portions l9 provide the parts corresponding with those designated by the reference character 36 of Figure 13 considerably higher and disposed beyond the sides of the leaves of the spring with which employed, so as to engage the edges of the spring band and sides of the adjacent spring leaves, thereby supplementing the effect of the edges defining the aperture 20 which receives the spring band. The portions 36 may have their end portions outwardly of the aperture 20 bevelled, as indicated at 42 The embodiment of my invention illustrated in Figures 26, 2'7 and 28 may be identical with that of Figures 23, 24 and 25, except that the relatively thick portions I9 are on the outside or other face of the relatively thin portion l8, as compared with the preceding embodiment, being rivetedl or spot welded to said face, as illustrated, and the end or bevelled portions 44 of the relatively thin portion l8 is provided with outstanding flanges 35 corresponding with the portions 35 of Figures 13, 14 and 15.

Referring now to the embodiment of my invention illustrated in Figures 29, 30 and 31, a spring plate H5 is there shown which corresponds generally with the plate 16 of Figures 23, 24 and 25, except that the rigidifying portion I9 for the relatively thin sheet metal portion l8 is formed as a unitary collar or ring rather than a pair of strips, as in the two preceding embodiments. The plate is desirably formed by blanking a central generally rectangular hole 2|! a little larger than is necessary to receive the band of the associated elliptic spring, flaring the edges up slightly, as indicated at 46, and inserting from the bottom the cast or drop forged generally rectangular tions 46 on a pressed plate portion W as shown in the embodiment of Figure 32, which portions in said embodiment fit over a horizontal flange 48 on the inserted ring I9 said portions I8 and H being then welded together, or otherwise connected, as indicated at 41 As in the preceding embodiment, the end portions 44 of the plate 16 may be bevelled or flared, as illustrated, in order to clear the plank embossments 29 or the side frame reinforcements 30.

Although preferred embodiments of my invention have been illustrated, it will be understood that modifications may be made Within the spirit and scope of the appended claims, and that the various features may be assembled as specifically disclosed, or a feature, or features of one embodiment may be alternatively employed instead of, or in addition to, a feature, or features, of another embodiment, or embodiments, without departing from my invention. It will also be understood that all of the embodiments, except the first, are only fragmentarily illustrated in plan, that is, approximately only one half of the plate l6 is illustrated in plan in Figure 13, said plate being symmetrical about the section line I4-|4. Likewise, the plate l6 shown in Figure 16, is symmetrical about the right-hand portion of the line 11-41, the plate I6 shown in Figure 20 is symmetrical about the line 2l--2|, the plate H3 shown in'Figure 23 is symmetrical about the line 2424, and the horizontal center line passing through the nib 34 the plate shown in Figure 26 is symmetrical about the line 212'l, and the horizontal center line passing through the nib corresponding to 34 of Figure 23, and the plate l6 shown in Figure 29, is symmetrical about the line 3030.

It will, of course, be understood that although the embodiments of Figures 13 to 22, inclusive, and 29 to 32, inclusive, have been shown as each provided with an aperture, corresponding with the aperture 20 in each plate of Figures 1, 2 and 3, I may, if desired, close the aperture, or apertures, in one, or more, of said plates, in each instance, by a web corresponding with the web l6 of Figures 4 to 8, inclusive, to form a spring band receiving pocket, or pockets, corresponding with the pocket [5' of Figures 4 to 8, inclusive, thereby further increasing the strength of the affected plate, or plates, and causing the associated spring band, or bands, to rest on a web, or webs, and be normally spaced closer to the associated band, or hands, than when constructed as illustrated.

I claim:-

1. A spring assembly comprising upper and lower plates, helical springs and leaf springs disposed between said plates and arranged to operate in parallel under an applied load, said leaf springs being held together by band means, the load carrying surfaces of said helical springs contacting the adjacent surfaces of said plates, said plates comprising a relatively thick portion adapted to provide a seat for the leaf springs and receive and position said band means, and a relatively thin portion rigidly connected thereto.

and provided with means for centering said helical springs.

2. A spring assembly comprising upper and lower plates, helical springs and leaf springs disposed between said plates and arranged to operate in parallel under an applied load, said leaf springs being held together by band means, the load-carrying surfaces of said helical springs contacting the adjacent surfaces of said plates,

5 portion being provided with means for centering said helical springs.

3. A spring assembly comprising upper and lower plates, helical springs and leaf springs disposed between said plates and arranged to operate in parallel under an applied load, said leaf springs being held together by band means, the load-carrying surfaces of said helical springs contacting the adjacent surfaces of said plates,

each plate being composite and comprising a rell5 at'ively thick portion joining a pairof relatively thin portions rigidly secured thereto, said relatively thick portion comprising a generally rectangular receptacle defined by edge portions at the ends of greater height than at the sides in order to engage alongside the adjacent leaf of said leaf spring as well as surround the band means thereof.

4. A spring plate, for a truck spring unit comprising helical and handed leaf springs, consist-= ing of a relatively thin pressed steel portion and a relatively thick portion rigidly secured together, said first-mentioned portion serving to engage said helical springs and said last-mentioned portion serving to provide a seat for said leaf springs and position the band means thereof.

5. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a pair of relatively thin pressed steel portions joined by a relatively thick cast portion rigidly secured thereto, said pressed steel portions serving to engage said helical springs and said cast portion serving to position the band means .of said leaf springs.

6. A spring plate, for a truck spring unit comprising both cast and pressed steel portions, said cast portion being formed with a generally rectangular receptacle defined by side portions relatively low, and end portions of greater height than said side portions in order to engage alongside the adjacent leaf of a banded leaf spring as well as surround the band of said spring.

7. A spring plate, fora truck spring unit comprising helical springs and leaf springs, said leaf springs being held together by band means, said plate having a plurality of pressed portions held together by and rigidly secured to a cast portion.

- 8. A composite spring plate comprising a relatively thick portion rigidly connected-to a relatively thin portion, said relatively thick portion 55 serving to seat and position a banded leaf spring by engaging the band thereof. I

9. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a pair of relatively thin pressed steel por- Q tions formed with helical spring centering collars and flanges on portions disposed between said collars, and a relatively thick portion cast around said flanges for connecting said portions,

. said cast portion serving to position the band of as said leaf spring.

10. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a pair of relatively thin pressed steel portions and a relatively thick portion rigidly seqo cured to said thin portions by being cast around 1 11. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a pair of relatively thin pressed steel portions and a relatively thick portion connecting said pair of thin portions, said relatively thin portions having strips slit and embossed outwardly therefrom and embedded in the metal of said cast portion.

12. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a pair of relatively thin pressed steel helical spring seating portions joined by a relatively thick leaf spring seating portion, the adjacent edge portions of said thin and thick portions being secured together.

13. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a relatively thin portion apertured to receive the band of said leaf spring, opposite edge portions defining said aperture being reinforced by relatively thick metal strips.

14. A spring plate, for a truck spring unit comprising helical and handed leaf springs, consisting of a relatively thin pressed steel portion and a relatively thick leaf spring seating collar por-.

tion rigidly secured-thereto, said collar portion being adapted to receive the band of said leaf springs, and having sections at the corners of greater height than side portions in order to engage alongside the adjacent leaf of said springs.

15. A spring plate for a truck spring unit comprising a relatively thin portion formed with a generally rectangular aperture and means ad- 'lower plates, helical springs and banded leaf springs disposed between said plates and arranged to operate in parallel under an applied load, said leaf springs being held together by band means, the load-carrying surfaces of said helical springs contacting the adjacent surfaces of said plates, said plates having spring band receptacles including relatively thick leaf spring seating portions adapted to lie on four sides of the bands to prevent lateral shifting thereof and cornerportions of greater height than said side portions in order to engage alongside the adjacent leaves of said springs.

1'7. A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a relatively thin portion apertured toreceive a band of said leaf springs, edge portions defining said aperture being reinforced by metal thicker than said plate in order to provide seating portions for the adjacent leaf spring.

18 A spring plate, for a truck spring unit comprising helical and banded leaf springs, consisting of a relatively thin portion apertured to receive the band of said leaf springs, opposite edge portions defining said aperture being reinforced by relatively thick metal strips, end portions of said strips being angularly disposed to embrace adjacent portions of said leaf springs therebetween.

DONALD S. BARROWS. 

